tbuckley/cabot-search huggingface dataset:
Abstract 4248: HFB200603, a novel anti-BTLA monoclonal antibody that provides therapeutic potential for immune escape and synergizes with anti-PD-1 treatment
Authors: Juying Li, Qian Zhang, Bingqing Shen, Manan Shah, Mingjie Chen, Sharon Li, Ling Dong, Francisco Adrian, Liang Schweizer
Journal: Cancer Research (2022)

Abstract BTLA is a co-inhibitory immune checkpoint molecule sharing sequence and structural homology with PD-1 and CTLA4. Ligation of HVEM with BTLA induces recruitment of SHP1 and SHP2, and triggers inhibition of T cell proliferation and cytokine production. In melanoma, HVEM is described to have a broader expression than PD-L1 and constituted a negative prognostic marker; in PD-L1 negative NSCLC, the expression of HVEM has been shown to contribute to immune escape. Therefore BTLA-HVEM axis could play an important role in the immune escape, thus BTLA blockade in combination with PD-1/PD-L1 blockade could represent an effective therapeutic option. Using our proprietary microfluidic-based single cell platform CelliGO™, we identified a series of anti-human BTLA antibodies that were characterized for their binding affinity, cross-reactivity, selectivity and functional activity. Amongst them, HFB200603 was identified as a single-digit nanomolar binder to human and cynomolgus BTLA, capable of reversing HVEM-mediated immune suppression in a BTLA-HVEM reporter system and in a primary CD4+ T cell proliferation assay. HFB200603 showed synergistic effect with anti-PD-1 to enhance IFN-γ production in an MLR assay, and demonstrated favorable developability and pharmacokinetic profiles. Profiling of tumor infiltrating lymphocytes demonstrated that BTLA+PD-1+ T cells are present in melanoma, NSCLC, and HCC. Blockade of the BTLA-HVEM interaction with HFB200603 alone or in combination with anti-PD-1 led to increases in IFN-γ, CXCL9, IP-10 and other proinflammatory cytokines in primary dissociated tumor cultures. Based on its favorable pharmacological activity and excellent developability, HFB200603 is currently being developed as a potential novel immunotherapy coupled with a patient biomarker strategy derived from HiFiBiO’s Drug Intelligent Science (DIS™) single-cell immune profiling platform. Citation Format: Juying Li, Qian Zhang, Bingqing Shen, Manan Shah, Mingjie Chen, Sharon Li, Ling Dong, Francisco Adrian, Liang Schweizer. HFB200603, a novel anti-BTLA monoclonal antibody that provides therapeutic potential for immune escape and synergizes with anti-PD-1 treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4248.
Abstract 2301: Targeting the MUVB complex or downstream G2/M proteins potentiates CDK4/6 inhibitor efficacy in breast cancer
Authors: Leslie Cuellar-Vite, Kristen Weber-Bonk, Ruth A. Keri
Journal: Cancer Research (2022)

Abstract Uncontrolled progression through the cell cycle sustains the growth and progression of cancer. The cell cycle is comprised of 4 phases that are tightly regulated by two key transcriptional modulators, RB-E2F and MUVB complexes that regulate gene expression during the G1/S and G2/M cell cycle transitions, respectively. Target transcriptomes of both complexes overlap, suggesting that maximal inhibition of cell cycle progression, requires targeting both. Inhibitors that regulate the RB-E2F signaling axis have been FDA approved for treatment of a subset of breast cancers. These drugs specifically inhibit two kinases involved in the cell cycle known as CDK4 and CDK6. Palbociclib and abemaciclib, CDK4/CDK6 inhibitors (CDK4/6i), decrease cell proliferation by inducing a G1 cell cycle arrest. In contrast to CDK4/6, we previously reported that the activity of MUVB complex can be repressed using inhibitors of BET proteins, including the tool compound, JQ1. We hypothesized that dual targeting of MUVB and CDK4/CDK6 will synergize in breast cancer models to further decrease growth. To test this hypothesis, we assessed the impact of growth by adding JQ-1 to CDK4/6i in multiple intrinsically resistant cell lines. We found that addition of JQ-1 reduced IC50 of CDK4/6i by 60-75% and that the combination displayed synergistic growth suppression. Mechanistically, analysis of mRNA and protein expression revealed that the combination had greater ability to suppress expression of proteins that are MUVB target genes, G2/M, compared to single agents. We found through genetic and pharmacological approaches that inhibition of G2/M proteins Aurora Kinase A and NEK2 mediated CDK4/6i inhibitor response. Preclinical xenograft models confirmed that combined inhibition of CDK4/6 and MUVB, NEK2, or Aurora Kinase A can synergistically suppress tumor growth. Together, these results indicate that dual targeting of distinct phases of the cell cycle should be a more efficacious approach for suppressing breast cancer growth and provide a potential approach for blocking the acquisition of resistance to CDK4/6 inhibitors, a major clinical challenge for the treatment of luminal breast cancer. Citation Format: Leslie Cuellar-Vite, Kristen Weber-Bonk, Ruth A. Keri. Targeting the MUVB complex or downstream G2/M proteins potentiates CDK4/6 inhibitor efficacy in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2301.
Abstract 1643: B-hIL12A/hIL12B/hIL12RB1/hIL12RB2: A novel animal model for generation of IL12 therapies
Authors: Linlin Wang, Chang Liu, Veronika Chromikova, Ruili Lyu, Tianquan Jin, Mari Kuraguchi
Journal: Cancer Research (2022)

Abstract The pro-inflammatory cytokine, interleukin 12 (IL12), is primarily responsible for cell-mediated immunity and is chiefly produced by antigen presenting cells. Prior preclinical studies elucidated a promising role for IL12 mediating anti-tumor effects, however, clinical studies using cancer patients showed disappointing efficacy results, as well as severe adverse effects, with administration of systemic IL12 therapies. Intriguingly, progress in targeted delivery to the tumor microenvironment renewed high expectations on IL12 as a promising anti-tumor drug either alone or in combination due to its ability to inhibit and/or reprogram immunosuppressive cell subsets. Therefore, to evaluate the efficacy of IL12 and IL12 analogs in preclinical studies, Biocytogen has successfully generated a novel hIL12A/hIL12B/hIL12RB1/hIL12RB2 knock-in mouse strain. In this mouse model, the full coding sequences (CDS) of the mouse Il12a or Il12b gene were replaced by their human counterpart IL12A or IL12B gene sequences respectively. In addition, chimeric CDS, composed of human IL12RB1 or IL12RB2 extracellular region plus mouse Il12rb1 or Il12rb2 cytoplasmic region, was inserted into the mouse endogenous gene locus in in these animals, to express an IL12 receptor (IL12R) capable of recognizing human IL12 signaling. Expression analysis by RT-PCR detected human IL12A/IL12B/IL12RB1/IL12RB2 mRNA in humanized mice but not in wild-type mice. Additionally, human IL12 p70 was successfully detected in the serum of humanized mice by ELISA. The immune cell subpopulations in spleen, blood, and lymph node did not differ between humanized mice and wild-type mice suggesting no impact on cell differentiation and maturation. Anti-tumor activity of a modified human IL12 was assessed in humanized mice bearing colon cancer MC38 cells and showed tumor inhibitory effects. Moreover, the tumor growth recovered when the administration of the drug was stopped. Altogether, B-hIL12A/hIL12B/hIL12RB1/hIL12RB2 humanized mice provide a promising preclinical efficacy model for human IL12 therapy alone or in combination. Keywords: IL12, humanized mice, antibody efficacy Citation Format: Linlin Wang, Chang Liu, Veronika Chromikova, Ruili Lyu, Tianquan Jin, Mari Kuraguchi. B-hIL12A/hIL12B/hIL12RB1/hIL12RB2: A novel animal model for generation of IL12 therapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1643.
Abstract 2515: Estrogen regulates the immune microenvironment of colorectal cancer liver metastases
Authors: Yasmine Benslimane, Sarah Lapin, Julien Chambon, Matthew Leibovitch, Stéphanie Perrino, Pnina Brodt
Journal: Cancer Research (2022)

Abstract Liver metastases (LM) remain a major cause of cancer-related death and many cancers preferably metastasize to the liver due to its unique anatomical location, rich blood supply and immune-tolerant microenvironment. Up to 50% of colorectal carcinoma patients develop LM during their disease and this is associated with a poor prognosis. Our laboratory previously identified a sexual dimorphism in the regulation of the immune microenvironment (IME) of LM and showed that estrogen could promote the accumulation of myeloid-derived suppressor cells (MDSCs) and Tregs in the liver in response to invading cancer cells. The objective of this study was to elucidate the role of estrogen in the recruitment and polarization of monocytes/macrophages and in the accumulation and phenotype of natural killer (NK) cells in the IME of colorectal carcinoma LM (CRCLM). Moreover, we sought to determine the therapeutic potential of Selective Estrogen Receptor Degrader (SERD) therapy in tumor bearing female mice. In estrogen-competent female mice bearing CRCLM, we found increased gene and protein expression of the immunosuppressive cytokine TGF-β, and inversely a decrease in the pro-inflammatory cytokine TNF-alpha. Furthermore, we identified a significant increase of newly recruited, immunosuppressive CD68+F4/80+CD163+ M2 macrophages, as compared to estrogen-depleted (ovariectomized) mice. The recruitment of pro-inflammatory CD68+F4/80+TNF-alpha+ M1 macrophages, and the accumulation of the highly cytotoxic NK1.1+ CD49a+ liver NK cells were increased in estrogen-depleted female mice and could be restored upon estrogen supplementation. Moreover, treatment of female mice with the SERD Fulvestrant, markedly reduced the number of CRCLM compared to vehicle-treated mice, and significantly reduced the cell frequencies and counts of recruited myeloid cells and M2 macrophages in the liver. Taken together, our results identify estrogen as a critical regulator of an immunosuppressive tumor ME in the liver and a potential therapeutic target. Funding by the Canadian Institute of Health Research is gratefully acknowledged. Citation Format: Yasmine Benslimane, Sarah Lapin, Julien Chambon, Matthew Leibovitch, Stéphanie Perrino, Pnina Brodt. Estrogen regulates the immune microenvironment of colorectal cancer liver metastases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2515.
Abstract 904: Neural stem cells of the subventricular zone evolve into tumors around the resection cavity after surgical resection of glioblastoma via the CXCL12/CXCR4 axis
Authors: Xue Li, Hyun Jung Kim, Jeong Ho Lee, Hong-Gyun Wu, Joo Ho Lee
Journal: Cancer Research (2022)

Abstract Glioblastoma multiforme (GBM) is the most common lethal primary brain tumor. Neural stem cells (NSCs) harboring cancer-driving mutations in the subventricular zone (SVZ) have recently been reported as the cells of origin for human glioblastoma (GBM) through migration. However, the pathological role of residual tumor-initiating NSCs (tNSCs) in the SVZ is undetermined for local recurrent tumor after surgical removal of the primary tumor. After the primary resection of GBM, most recurrences still appear as local tumors around the resection cavity (RC). Accordingly, we hypothesized that, after complete removal of the primary tumor, the tNSCs in SVZ might be the source for tumor construction at RC. Here, we examined the role of tNSCs in the development of local tumors around RC using a mouse model and genetic analysis of human tissues. First, cancer-driving mutations, including Trp53, Pten, and Egfr mutations, were introduced to NSCs in SVZ through in vivo electroporation, and the RC was generated in the remote cortex through stereotaxic resection. We found that the NSCs harboring driver mutations migrated specifically to the RC through the aberrant growth of oligodendrocyte-precursor cells (OPCs). Furthermore, the SVZ-originated cells constituted the GBM around the RC at four weeks post-resection in 64% of mouse models. Second, we performed deep sequencing of longitudinal matched tissues consisting of (i) normal SVZ away from the tumor, (ii) primary tumor, (iii) recurrent tumor, and (iv) blood in the patients with GBM, IDH wildtype. We found that the dominant clones of recurrent tumors genetically arose from the SVZ, not directly from the primary tumor. Third, the CXCR4/CXCL12 axis was upregulated through migration from the SVZ and tumor formation at the RC compared with primary tumors without the RC in mouse models. Blockage of the CXCR4/CXCL12 axis decreased the number of immigrating OPC lineage cells specifically and improved tumor control and survival rates. Taken together, our results reveal that the residual tNCSs harboring cancer-driving mutations in the SVZ can re-construct tumors after surgical resection of GBM. Blocking CXCL12/CXCR4 might be a potential treatment strategy for preventing the main local failures after resection. Citation Format: Xue Li, Hyun Jung Kim, Jeong Ho Lee, Hong-Gyun Wu, Joo Ho Lee. Neural stem cells of the subventricular zone evolve into tumors around the resection cavity after surgical resection of glioblastoma via the CXCL12/CXCR4 axis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 904.
Inhaled seralutinib exhibits potent efficacy in models of pulmonary arterial hypertension
Authors: Anna Galkin, Ravikumar Sitapara, Bryan Clemons, Eduardo Garcia, Michael Kennedy, David Guimond, Laura L. Carter, Ashley Douthitt, Robin Osterhout, Aneta Gandjeva, Deborah Slee, Luisa Salter-Cid, Rubin M. Tuder, Lawrence S. Zisman
Journal: European Respiratory Journal (2022)

Signalling through platelet-derived growth factor receptor (PDGFR), colony-stimulating factor 1 receptor (CSF1R) and mast/stem cell growth factor receptor kit (c-KIT) plays a critical role in pulmonary arterial hypertension (PAH). We examined the preclinical efficacy of inhaled seralutinib, a unique small-molecule PDGFR/CSF1R/c-KIT kinase inhibitor in clinical development for PAH, in comparison to a proof-of-concept kinase inhibitor, imatinib.Seralutinib and imatinib potency and selectivity were compared. Inhaled seralutinib pharmacokinetics/pharmacodynamics were studied in healthy rats. Efficacy was evaluated in two rat models of PAH: SU5416/Hypoxia (SU5416/H) and monocrotaline pneumonectomy (MCTPN). Effects on inflammatory/cytokine signalling were examined. PDGFR, CSF1R and c-KIT immunohistochemistry in rat and human PAH lung samples and microRNA (miRNA) analysis in the SU5416/H model were performed.Seralutinib potently inhibited PDGFRα/β, CSF1R and c-KIT. Inhaled seralutinib demonstrated dose-dependent inhibition of lung PDGFR and c-KIT signalling and increased bone morphogenetic protein receptor type 2 (BMPR2). Seralutinib improved cardiopulmonary haemodynamic parameters and reduced small pulmonary artery muscularisation and right ventricle hypertrophy in both models. In the SU5416/H model, seralutinib improved cardiopulmonary haemodynamic parameters, restored lung BMPR2 protein levels and decreased N-terminal pro-brain natriuretic peptide (NT-proBNP), more than imatinib. Quantitative immunohistochemistry in human lung PAH samples demonstrated increased PDGFR, CSF1R and c-KIT. miRNA analysis revealed candidates that could mediate seralutinib effects on BMPR2.Inhaled seralutinib was an effective treatment of severe PAH in two animal models, with improved cardiopulmonary haemodynamic parameters, a reduction in NT-proBNP, reverse remodelling of pulmonary vascular pathology and improvement in inflammatory biomarkers. Seralutinib showed greater efficacy compared to imatinib in a preclinical study.
Abstract 1524: Expression of GDNF and its receptors in glioblastoma
Authors: Jesper D. Ewald, Arnon M. Knudsen, Bjarne W. Kristensen
Journal: Cancer Research (2022)

Abstract Introduction: Glioblastoma is the most aggressive primary brain cancer and one of the most lethal types of cancer overall. Despite multimodal treatment strategies, the prognosis is poor with a median survival of approx. 15 months. Although neurotrophic factors are of major importance in the nervous system, their role in brain cancer is still not fully understood. We focused on the glial cell line-derived neurotrophic factor (GDNF), which has been shown to play a role in growth and migration in glioblastoma. The aim of this study was to investigate the expression of GDNF and it primary receptor GFRA1, as well as the other GDNF family receptors GFRA2-4 and RET. Methods: Tissue sections from 10 glioblastoma patients were stained with antibodies against GDNF and each of the receptors. GDNF stainings were performed on frozen tissue slides, while receptor stainings were performed on formalin-fixed paraffin-embedded tissue sections. The area fractions of positive staining were quantified with a software-based classifier. Double immunofluorescence stainings with the different markers and Iba1 as well as GFAP were performed to assess expression in microglia/macrophages and tumor cells, respectively. Results: GDNF staining was observed in five of ten patient specimens, whereas GFRA1 and GFRA2 staining was observed in all samples. GFRA1 and GFRA2 staining was seen in the membrane and cytoplasm with a mean area fraction of GFRA1 staining at 31% (range: 7-56%), and a mean area fraction of GFRA2 staining at 3% (range: 0.2-7%). GFRA3, GFRA4 and RET were not expressed in glioblastoma tissue. Double immunofluorescence stainings demonstrated co-expression of GFRA1 and GFAP, while co-expression of GFRA1 and IBA1 was limited. Conclusion and perspectives: Our results suggest that GDNF and GFRA1 are widely expressed in glioblastoma tumor tissue, but GFRA2 is also expressed and may play a role in glioblastoma biology. Additional stainings are being established to clarify cellular expression and expression levels of GDNF and its receptors. Citation Format: Jesper D. Ewald, Arnon M. Knudsen, Bjarne W. Kristensen. Expression of GDNF and its receptors in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1524.
Abstract 1644: Generation and validation of humanized GARP mice for testing novel anti-human GARP antibodies
Authors: Ruili Lyu, Huilin Li, Jenna Frame, Yuelei Shen
Journal: Cancer Research (2022)

Abstract GARP is a type I transmembrane protein expressed on regulatory T cells (Tregs) and platelets. GARP expression has been shown to play an important role in the modulation of latent TGF-β1 activity by regulatory T lymphocytes (Tregs), and thus, GARP has emerged as an important regulator of peripheral immune tolerance. While GARP expression is critical for homeostasis, increased GARP expression on Tregs is associated with elevated immunosuppression in the context of tumor biology. Because of these immunomodulatory roles, targeting GARP in the context of oncologic or other diseases is of significant interest. Thus, the development of mouse models for safety and efficacy evaluation of GARP-targeted therapeutics prior to clinical trials is needed. To facilitate assessment of novel anti-human GARP antibodies, Biocytogen has generated a humanized GARP mouse model for in vitro functional validation and in vivo efficacy evaluation assays. Using CRISPR-based gene editing technology, the exons of the mouse Garp gene that encode the extracellular domain were replaced by the human GARP counterpart. mRNA Expression of the human GARP extracellular domain was confirmed in splenocytes isolated from homozygous humanized mice. Expression of human GARP was readily detected in FoxP3+ Treg cells isolated from the spleen of humanized GARP mice as assessed by flow cytometry. Importantly, the frequency of FoxP3+ Tregs and other mature leukocyte subpopulations, including T and B lymphocytes, Natural killer cells, dendritic cells, granulocytes, and monocytes/macrophages, was also similar in the blood and spleen of humanized GARP mice compared to wild-type mice. Subsequent in vivo efficacy assays using the MC38 tumor model demonstrated efficacy of the anti-human GARP antibody in slowing tumor growth in humanized GARP mice. Furthermore, combination of anti-human GARP and anti-mouse PD-1/PD-L1 blockade resulted in a significantly greater tumor inhibition than monotherapies. In summary, GARP humanized mice are a powerful platform for preclinical evaluation of anti-human GARP antibodies for cancer treatment. Citation Format: Ruili Lyu, Huilin Li, Jenna Frame, Yuelei Shen. Generation and validation of humanized GARP mice for testing novel anti-human GARP antibodies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1644.
Abstract 5183: LGR5 CAR-T cells: A novel potential treatment against high grade serous ovarian cancer
Authors: Wanqi Wang, Veronika Bandara, Noor Lokman, Silvana Napoli, Batjargal Gundsambuu, Martin Oehler, Simon C. Barry, Carmela Ricciardelli
Journal: Cancer Research (2022)

Abstract Ovarian cancer is second leading cause of cancer-related mortality among gynecological cancers in the Western world. Although initial responses to 1st line treatment is high, over 75% of patients eventually relapse and acquire chemotherapy resistance, which is the primary cause of ovarian cancer treatment failure. New therapies to improve patient outcome are therefore urgently required. Chimeric antigen receptor T (CAR-T) cell therapy is an adoptive immunotherapy that is currently being used to treat some blood cancers. CAR-T cell therapies have so far been less effective against solid cancers, due in part to the absence of suitable tumor-associated antigen (TAA).This study has investigated whether Leucine-rich repeat-containing G protein-coupled receptor 5, LGR5) is a suitable target for CAR-T cell therapy for ovarian cancer. We found that LGR5 is highly expressed in HGSOC cancer lines (COV318, COV362 and OAW28) and increased in HGSOC tissues following relapse with chemotherapy resistant disease. We assessed the cytotoxic effects of LGR5-CAR-T cells on a range of ovarian cancer cell lines and primary serous ovarian cancer cells derived from patient ascites in vitro by MTT and 3D spheroid assays. We demonstrated that LGR5-CAR-T cells were cytotoxic and significantly inhibited survival of ovarian cancer cell lines (COV318, COV362) that express high levels of LGR5 but not SKOV3 or OV90 that express lower LGR5 levels in monolayer culture. In addition, LGR5-CAR-T cells were cytotoxic and significantly inhibited survival of primary serous ovarian cancer cells compared to un-transduced CD3+ T cells. LGR5 CAR-T cells also exhibited anti-tumor activity against ovarian cancer cell lines (COV318, COV362 &amp; OAW28) and primary serous ovarian cancer cells in vitro using 3D-spheroid culture assays. This study demonstrates that LGR5-CAR-T cells have great potential to be developed as a novel immunotherapy for ovarian cancer. Citation Format: Wanqi Wang, Veronika Bandara, Noor Lokman, Silvana Napoli, Batjargal Gundsambuu, Martin Oehler, Simon C. Barry, Carmela Ricciardelli. LGR5 CAR-T cells: A novel potential treatment against high grade serous ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5183.